I am in the process of having a new home built in the Houston Texas area by a local builder. Unfortunately, the plumbing or drain for the washer in the utility room was placed in the slab 16 inches from the wall and ended up in the closet under the stairs. They are telling me they can move the drain without jeopardizing the integrity of the slab or creating future drain problems with the washer. My concern is possible damage to the slab, drainage problems in the future if moved and the angle of the drain if left in current location. If the drain is left under the stairs in the back lower part of the closet, it could be walled off and no one would see it. However, I am concerned about the correct angle and resale value on the house. Any advice would be appreciated?

I see a couple of possible choices, depending on the exact dimensions involved, and if a post tensioned slab or not, as some determining factors if they are possible or not.

1) Chip out the slab and re-route the clothes washer drain line to where it should be. If the slab is post tensioned, there may be, or may not be, a post tension tendon in the way - if there is, that is not a good thing but could be engineered around it and be okay. If the slab is not post tensioned, there may be, or may not be, reinforcing steel in the way, but that is typically easier to engineer/work around (may not require an engineer for this where a post tension tendon definitely would require an engineer for any work involving its removal/relocation/etc).

In doing anything with the slab, make sure that any disturbed soil is properly re-compacted, and make sure that any termite pretreatment is re-pretreated. Chipped out/cut out concrete repair areas need to be doweled into place with dowels epoxied into the existing concrete and into the repaired area to maintain the integrity of the repaired area.

2) From where the clothes washer drain comes up out of the floor, there may be a short enough distance to just route the drain line around the wall to the desired location, with the drain line at the required slope, and the height for the clothes washer stand pipe and trap to meet the required/allowed minimum/maximum heights.

I suspect that almost any new house one buys has things like this which where caught and corrected by the builder without the new home buyer ever knowing it was done incorrectly, therefore as long as the repairs are done correctly there should not be any negative effect on the value of the house (because almost all other homes have similar repairs, just the owners are not aware of them - this is quite a common occurrence).

The key, though, is that the work be corrected "properly" and short cuts, which could potentially result in the original problem showing up in the future, are not taken.